1. Field of the Invention
This invention relates generally to the field of packaging, and more specifically to dispensing closures that are designed to dispense product from a container having an unthreaded finish portion.
2. Description of the Related Technology
Plastic dispensing closures are in wide use throughout the world for packaging liquid or semi liquid products and in particular for packaging comestible foodstuffs such as ketchup, mustard or syrups. A dispensing closure typically includes structure that permits it to be secured to a finish portion of a mating container, a dispensing orifice and some type of structure such as a fliptop lid for selectively opening and closing the dispensing orifice.
Many dispensing closures are provided with threaded inner surfaces that are constructed and arranged to mate with helical threads that are provided on the finish portion of the container to which they are attached. Such closures however are typically easily removed from the container by simply unscrewing the closure from the finish portion of the container.
In certain packaging applications it is preferred that the closure be constructed so that it is difficult to remove from the container. For example, in the packaging of brand-name comestible foodstuffs such as ketchup and mustard that are intended for restaurant use, the manufacturer has an interest to make sure that the restaurant does not replenish the brand-name product with an inferior substitute by simply removing the dispensing closure, refilling the container and replacing the dispensing closure. The inferior quality of the substitute product would wrongfully be associated in customer's minds with the original brand-name product if this were permitted to occur.
Accordingly, many dispensing closures for such packaging applications are designed to be applied to a container that has an unthreaded finish with retention structure such as an annular flange. These types of dispensing closures typically include some type of locking structure that slips over the retention structure when the closure is originally being applied to the container but that engages an underside of the retention structure after the closure has been applied to the container so as to make it difficult to remove the closure from the container. Unfortunately, however, it is possible using great force to remove many these dispensing closures from the container and to reapply them to the container after the container has been refilled.
A need exists in the packaging industry for a dispensing closure that is designed to be applied to a container having an unthreaded finish portion that may not be reapplied to the container after it has been removed.